Fuse arrays are used as nonvolatile memory blocks for the storage of binary data. The memory blocks are typically programmed by selectively “blowing” certain fuses while leaving others in their conductive state. To “blow” a fuse, high voltages and currents are passed through the fuse, generating enough heat to melt the fuse element. This type of memory can be written once and is then Read Only Memory (ROM).
The high voltages and currents used to program such a memory block present several issues that have to be addressed. For example, a separate high voltage power supply and additional circuitry are needed. Additionally, parasitic resistances within the fuse and its connections can create undesirable effects. Also, collateral damage to surrounding structures in the integrated circuit may occur when a fuse is blown.
Throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements.